Before this fix, a negative constant in a view or rule
might be dumped as, say, -42::integer, which is subtly incorrect: it
should be (-42)::integer due to
operator precedence rules. Usually this would make little
difference, but it could interact with another recent patch
to cause PostgreSQL to
reject what had been a valid SELECT
DISTINCT view query. Since this could result in
pg_dump output failing to
reload, it is being treated as a high-priority fix. The
only released versions in which dump output is actually
incorrect are 8.3.1 and 8.2.7.